AI-powered condenser water temperature reset reduced chilled water energy consumption by 5.9% at a New York City hospital — independently validated through the ConEdison RTEM rebate program.
The Challenge
HVAC systems are the largest single energy consumer in hospitals — typically accounting for 52% or more of total facility energy use. At this New York City cancer center, the 1,200 TR chiller plant was operating with static condenser water temperature set-points that did not respond to ambient wet-bulb conditions.
Healthcare facilities present a unique optimization challenge: patient safety and indoor air quality requirements are non-negotiable, which means any HVAC control changes must maintain strict temperature, humidity, and filtration standards. Optimization had to be delivered without compromising clinical environment requirements.
HVAC accounts for approximately 52% of total facility energy in this hospital — making it the single largest lever for reducing energy costs and carbon emissions without capital investment.
Building Profile
| Facility Type | Specialist cancer treatment hospital |
| Location | New York City, New York, USA |
| Chiller Plant Capacity | 1,200 TR |
| HVAC Energy Share | ~52% of total facility energy |
| Optimization Algorithm | Dynamic Condenser Water Temperature Reset |
| M&V Protocol | IPMVP Option B (12 months) R² = 0.987 |
| Utility Validation | ConEdison RTEM Rebate Program |
The Exergenics Approach
Exergenics deployed a Dynamic Condenser Water Temperature Reset Algorithm — implemented directly within the facility's BMS — to continuously optimize condenser water set-points based on real-time ambient wet-bulb temperature, chiller load, and system constraints. The approach was specifically designed to remain within all healthcare environment requirements.
Exergenics mapped all clinical environment requirements — temperature ranges, humidity tolerances, and failsafe conditions — into the optimization model constraints, ensuring patient safety and regulatory compliance were maintained throughout all operating modes.
The algorithm continuously calculates the optimal condenser water temperature set-point based on ambient wet-bulb conditions and real-time chiller loading — reducing compressor lift and lowering energy consumption without affecting chilled water supply temperatures or system reliability.
Savings were verified through a full 12-month IPMVP Option B measurement and verification study. The regression model achieved an R² of 0.987, demonstrating exceptional predictive accuracy. Results were independently confirmed through the ConEdison RTEM rebate program.
Verified Results
All results were independently verified through a 12-month IPMVP Option B measurement and verification study and confirmed by the ConEdison Real-Time Energy Management (RTEM) rebate program.
| Outcome | Verified Result |
|---|---|
| Annual Energy Reduction | 5.9% reduction in chilled water system energy |
| Annual kWh Savings | 63,077 kWh per annum |
| Carbon Avoided | 26 tCO₂ per annum |
| M&V Model Accuracy | R² = 0.987 (12-month IPMVP Option B) |
| Utility Validation | Confirmed by ConEdison RTEM Rebate Program |
| Algorithm | Dynamic Condenser Water Temperature Reset (BMS-integrated) |
| Capital Expenditure | $0 — software-only, BMS-integrated deployment |
Exergenics delivers utility-validated HVAC energy savings for hospitals and healthcare facilities — with no capital expenditure, no operational risk, and full clinical compliance.